Assessment of groundwater vulnerability to pollution was conducted by the DRASTIC method in central Poland, in the Vistula River valley. The results of this study have shown that 68.18% of the study area has a low pollution potential and 31.2% has a medium pollution potential. Single-parameter and map removal sensitivity analyses were conducted to evaluate the relative importance of the parameters for aquifer vulnerability. Both analyses showed that by far the most significant parameter of the DRASTIC vulnerability index in the study area is the depth to the water table. Although the water table in more than 90% of the study area is shallow, less than 3 m below ground level, the assessment shows that this does not lead to a high groundwater vulnerability.